ej25 swap into L SOHC version

Arg! I have done the swap. I have removed a 1.8l from my 95 OBDI L and installed a SOHC 2.5l from a 2001 (OBDII) car.

It depends... It will run perfectly fine off the 1.8 ECU, it will run rich though. if you want it act 100% like a 2.5 RS then change the harness and ECU Etc.

I did it cause my 1.8l had so many oil leaks i was sick of chasing down and wanted more power.

2.5 bolts right into the mounts and trans, i used a stock 2.5l flywheel clutch and pressure plate althoug the 1.8s will work.

Due to the idle air control setup and connections to the ECU, the 1.8 throttle body was retained. a blockoff plate was made to cover the idle air port on the newer 2.5 manifold.

the new style fuel injector connectors were spliced onto the 1.8 harness becuase i used the newer style injectors on the 01' 2.5.

crank and cam sensors, engne temp sensor, and oil press switch all plugged right in to the 1.8 wiring.

the temp gauge sensor was rewired, the older 1.8 had a small sensor with 1 wire whereas the newer 2,5 had a newer 3 wire sensor, i changed the connector to the newer sensor, blocked off two of the pins and ran the bottom wire to the temp guage.

I used the 1.8 coil pack and had plug wires made. if using a DOHC 2.5 stock 2.5 wires should work. I needed old style connectors on the coil end and newer style on the plug end. GOt them custom made and overnighted for 50 bucks from kingsborne wire werks.

EGR did not exist on the 2.5 so i hooked the harness to the solinoids which i retained and just plugged them off.

Knock sensor is not used

stock 1.8 intake and MAF sensor are used.

the only thing i can say to watch out for is the crank trigger on the timing sprocket that triggers the crank sensor.

the older cars it was all the same one, but for the newer (i think 2000 and up) there is a different ring on the manual trans cars. So if you want to use the 1.8 ECU you need to switch it over to the other timing spocket, or reuse the 1.8s

thats all i can think of.
Ive got over 7,000 miles on the 2.5 with the 1.8 ECU. I drive it hard too. it does run alittle too rich, occasionally when going WOT it bogs slightly cause when the ECU switches modes is over fuels, after a week i was used to this and learned to drive at 99% throttle and it does great, no problems. it will bog when really cold out for the same reason unless you let it warm up. if you start and drive it when cold it bogs if you get on it, if you let it warm up for a few min. it runs like normal.

Gas mileage on the 2.5 with the 1.8 ECU is around 26-28 MPG and i hit WOT at least 3 times every time i drive it.

Some vacuum lines will need to be rerouted, just sit down with a service manual and match them up. they will match up, just takes some time. My local dealer photocopied the pages i neededform the service manual for me. I am really happy with the results, it only cost me about 200 bucks because I already had the engine.